The present invention relates to a new structure of cooler-heater fan, particularly to a fan structure in which the fan body uses a spindle for rotation so as to enable the fan assembly to deliver air flow in a slanting direction.
(b) Description of the Prior Art
Heater fan are generally used in cold-weather area. The heater fan is differed from a cooler fan in that a heating apparatus is usually added behind the fan blade assembly. The heat generated from the heating apparatus is drawn by the fan blade so that hot air can be blown out. When the heating apparatus is shut off, the heater fan functions the same as the cooler fan. This is also the basic principle of the dual purpose cooler-heater fan.
However, the addition of the heating apparatus brings cut a safety concern. The heating apparatus, if not properly handled, can start a fire. Therefore, the use of the heating apparatus is restricted by the following:
1. The materials used to manufacture the heater fan have to be fire proof and be able to withstand a high temperature. These materials usually are more expensive.
2. For safety consideration, the heating apparatus in the heater fan has to be standardized. The heating apparatus has to be limited in power, and this indirectly confines the size of the heater fan.
3. A safety tilt switch is provided inside the heater fan. When the heater fan is placed in a tilted position exceeding a certain limit, the safety tilted switch automatically shuts off the heater power to the fan assembly. This feature is designed to prevent a fire in case the fan assembly is accidentally knocked over.
It can be seen from the above description that the safety requirement for the manufacturing of the heater fan is more critical than that for the cooler fan. Because of its compact size, most of the heater fans are designed to have a one-piece structure. Also because of the requirement of the safety tilt switch, the majority of the heater fans cannot deliver and air flow that is adjustable in a slanted direction. The Inventor, after accepting comments and recommendations from many users, has come up with a new structure for the cooler-heater fan in which the angle of the air flow is adjustable, thereby meeting the demand of the public.